Audio notification systems used for notifying information to occupants of a building or people within an outdoor environment such as a train station, a stadium, a slope in a skiing resort, etc. are commonly used today for notifying information such as evacuation alarms (e.g. fire alarms), alert messages, messages informing people about the departure and arrival of planes, busses and/or trains, advertising messages in department stores, etc. Similar audio notification systems may also be located on a vehicle for public transportation such as a plane, a buss, a train, a boat or somewhere else information is sent to people by audio. The audio notification system comprises a plurality of audio devices being arranged to emit audible sound.
Depending on the use of an audio notification system different problems exist.
For an audio notification system used for evacuation alarms it is crucial that all areas of a building, an outdoor environment or a vehicle for public transportation are covered such that in case of an emergency the evacuation alarm is notified to all occupants of the building, all people of the outdoor environment or all people of the vehicle for public transportation. However, it is difficult to test the audio notification system to check if all areas are covered. A common method to do this is to simultaneously put all the audio devices of the audio notification system in an alarm mode such that all the audio devices are emitting an audible evacuation alarm and then having a test person walking around in the building, outdoor environment or vehicle for public transportation to check if all areas are covered by the audible evacuation alarm. Moreover, such testing needs to be repeated at regular times in order to safeguard that the audio notification system is working properly.
In addition to the above problem of not covering all areas of a building, an outdoor environment or a vehicle for public transportation, a problem with audio notification systems used for alert messages, messages informing people about the departure and arrival of planes, busses and/or trains, advertising messages in department stores, etc is to safeguard so that the audible sound emitted by the audio devices of the audio notification system is of such quality that the information in the messages can be heard by the intended recipients. This is often troublesome to achieve; this since it is hard to properly adopt the audio level of the sound emitted from the different audio devices of the audio notification system such that no distortion is present or such that the audio level is not to weak resulting in that the messages are not perceived by the intended recipients.
Another problem, especially often present in audio notification systems spread over a big area, is that people will be hearing echoes from loudspeakers further away. Such a typical big area is a slope in a skiing resort.
A common problem with all audio notification systems of today is that if one or more audio device within the audio notification system are not working properly, the original set up of the audio notification system is outdated such that not all areas of the building, the outdoor environment or the vehicle for public transportation are covered or such that the quality of the audible sound is not good enough